The Bosses tab will let you customize settings for certain bosses, even the abilities consisting of timer bars and warnings. Under the Settings panel, you are mainly going to come across Bosses and Options. The settings panel of the addon can be opened by typing /dbm into the chat window or directly hitting on the minimap icon. Just install it, and directly start using it as you like. Deadly Boss Mods easily works without the need of any sort of customization.